The present invention relates to an objective of great or large overall length, i.e., of an objective whose overall length is substantially greater than the focal length of the objective.
Such objectives are required among other things to attain, under special mounting conditions, by way of illustration, large aperture ratios, i.e., the aperture number is less than 2.
Objectives of great overall length having such a low aperture number which achieve good imaging performance and are of simple construction have hitherto been unknown.
It is therefore an object of the present invention to provide an objective of great overall length having a low aperture number which achieves good imaging performance and is of simple optical construction.